[PATCH v3 1/5] Revert"x86/acpi: Set persistent cpuid <-> nodeid mapping when booting"

[Dou Liyang]

The mapping of "cpuid <-> nodeid" is established at boot time via ACPI
tables to keep associations of workqueues and other node related items
consistent across cpu hotplug.

But, ACPI tables are unreliable and failures with that boot time mapping
have been reported on machines where the ACPI table and the physical
information which is retrieved at actual hotplug is inconsistent.

Revert the mapping implementation so it can be replaced with a less error
prone approach.

Signed-off-by: Dou Liyang <douly.fnst@xxxxxxxxxxxxxx>
Tested-by: Xiaolong Ye <xiaolong.ye@xxxxxxxxx>
---
 arch/x86/kernel/acpi/boot.c   |  2 +-
 drivers/acpi/acpi_processor.c |  5 ---
 drivers/acpi/bus.c            |  1 -
 drivers/acpi/processor_core.c | 73 -------------------------------------------
 include/linux/acpi.h          |  3 --
 5 files changed, 1 insertion(+), 83 deletions(-)

diff --git a/arch/x86/kernel/acpi/boot.c b/arch/x86/kernel/acpi/boot.c
index ae32838..f6b0e87 100644
--- a/arch/x86/kernel/acpi/boot.c
+++ b/arch/x86/kernel/acpi/boot.c
@@ -710,7 +710,7 @@ static void __init acpi_set_irq_model_ioapic(void)
 #ifdef CONFIG_ACPI_HOTPLUG_CPU
 #include <acpi/processor.h>
 
-int acpi_map_cpu2node(acpi_handle handle, int cpu, int physid)
+static int acpi_map_cpu2node(acpi_handle handle, int cpu, int physid)
 {
 #ifdef CONFIG_ACPI_NUMA
 	int nid;
diff --git a/drivers/acpi/acpi_processor.c b/drivers/acpi/acpi_processor.c
index 4467a80..5d208a9 100644
--- a/drivers/acpi/acpi_processor.c
+++ b/drivers/acpi/acpi_processor.c
@@ -182,11 +182,6 @@ int __weak arch_register_cpu(int cpu)
 
 void __weak arch_unregister_cpu(int cpu) {}
 
-int __weak acpi_map_cpu2node(acpi_handle handle, int cpu, int physid)
-{
-	return -ENODEV;
-}
-
 static int acpi_processor_hotadd_init(struct acpi_processor *pr)
 {
 	unsigned long long sta;
diff --git a/drivers/acpi/bus.c b/drivers/acpi/bus.c
index 80cb5eb..34fbe02 100644
--- a/drivers/acpi/bus.c
+++ b/drivers/acpi/bus.c
@@ -1249,7 +1249,6 @@ static int __init acpi_init(void)
 	acpi_wakeup_device_init();
 	acpi_debugger_init();
 	acpi_setup_sb_notify_handler();
-	acpi_set_processor_mapping();
 	return 0;
 }
 
diff --git a/drivers/acpi/processor_core.c b/drivers/acpi/processor_core.c
index 611a558..a843862 100644
--- a/drivers/acpi/processor_core.c
+++ b/drivers/acpi/processor_core.c
@@ -278,79 +278,6 @@ int acpi_get_cpuid(acpi_handle handle, int type, u32 acpi_id)
 }
 EXPORT_SYMBOL_GPL(acpi_get_cpuid);
 
-#ifdef CONFIG_ACPI_HOTPLUG_CPU
-static bool __init
-map_processor(acpi_handle handle, phys_cpuid_t *phys_id, int *cpuid)
-{
-	int type, id;
-	u32 acpi_id;
-	acpi_status status;
-	acpi_object_type acpi_type;
-	unsigned long long tmp;
-	union acpi_object object = { 0 };
-	struct acpi_buffer buffer = { sizeof(union acpi_object), &object };
-
-	status = acpi_get_type(handle, &acpi_type);
-	if (ACPI_FAILURE(status))
-		return false;
-
-	switch (acpi_type) {
-	case ACPI_TYPE_PROCESSOR:
-		status = acpi_evaluate_object(handle, NULL, NULL, &buffer);
-		if (ACPI_FAILURE(status))
-			return false;
-		acpi_id = object.processor.proc_id;
-
-		/* validate the acpi_id */
-		if(acpi_processor_validate_proc_id(acpi_id))
-			return false;
-		break;
-	case ACPI_TYPE_DEVICE:
-		status = acpi_evaluate_integer(handle, "_UID", NULL, &tmp);
-		if (ACPI_FAILURE(status))
-			return false;
-		acpi_id = tmp;
-		break;
-	default:
-		return false;
-	}
-
-	type = (acpi_type == ACPI_TYPE_DEVICE) ? 1 : 0;
-
-	*phys_id = __acpi_get_phys_id(handle, type, acpi_id, false);
-	id = acpi_map_cpuid(*phys_id, acpi_id);
-
-	if (id < 0)
-		return false;
-	*cpuid = id;
-	return true;
-}
-
-static acpi_status __init
-set_processor_node_mapping(acpi_handle handle, u32 lvl, void *context,
-			   void **rv)
-{
-	phys_cpuid_t phys_id;
-	int cpu_id;
-
-	if (!map_processor(handle, &phys_id, &cpu_id))
-		return AE_ERROR;
-
-	acpi_map_cpu2node(handle, cpu_id, phys_id);
-	return AE_OK;
-}
-
-void __init acpi_set_processor_mapping(void)
-{
-	/* Set persistent cpu <-> node mapping for all processors. */
-	acpi_walk_namespace(ACPI_TYPE_PROCESSOR, ACPI_ROOT_OBJECT,
-			    ACPI_UINT32_MAX, set_processor_node_mapping,
-			    NULL, NULL, NULL);
-}
-#else
-void __init acpi_set_processor_mapping(void) {}
-#endif /* CONFIG_ACPI_HOTPLUG_CPU */
-
 #ifdef CONFIG_ACPI_HOTPLUG_IOAPIC
 static int get_ioapic_id(struct acpi_subtable_header *entry, u32 gsi_base,
 			 u64 *phys_addr, int *ioapic_id)
diff --git a/include/linux/acpi.h b/include/linux/acpi.h
index 673acda..63a7519 100644
--- a/include/linux/acpi.h
+++ b/include/linux/acpi.h
@@ -294,11 +294,8 @@ bool acpi_processor_validate_proc_id(int proc_id);
 int acpi_map_cpu(acpi_handle handle, phys_cpuid_t physid, u32 acpi_id,
 		 int *pcpu);
 int acpi_unmap_cpu(int cpu);
-int acpi_map_cpu2node(acpi_handle handle, int cpu, int physid);
 #endif /* CONFIG_ACPI_HOTPLUG_CPU */
 
-void acpi_set_processor_mapping(void);
-
 #ifdef CONFIG_ACPI_HOTPLUG_IOAPIC
 int acpi_get_ioapic_id(acpi_handle handle, u32 gsi_base, u64 *phys_addr);
 #endif
-- 
2.5.5